International Patent Publication Number WO 2005/104745 (Glaxo Group Limited), filed 27 Apr. 2005, discloses muscarinic acetylcholine receptor antagonists. In particular, WO 2005/104745 discloses 4-[hydroxy(diphenyl)methyl]-1-{2-[(phenylmethyl)oxy]ethyl}-1-azoniabicyclo[2.2.2]octane bromide, of formula (I), and a process for the preparation of this compound (Example 84):

4-[Hydroxy(diphenyl)methyl]-1-{2-[(phenylmethyl)oxy]ethyl)}1-azoniabicyclo[2.2.2]octane bromide may also be referred to as umeclidinium bromide.
International Patent Publication Number WO 2011/029896 (Glaxo Group Limited), filed 10 Sep. 2010, discloses an alternative preparation for an early intermediate, ethyl-1-azabicyclo[2.2.2]octane-4-carboxylate, in the multi-step synthesis of umeclidinium bromide.
There exists a need for an alternative process for the preparation of umeclidinium bromide. In particular, a process that offers advantages over those previously disclosed in WO 2005/104745 and WO 2011/029896 is desired. Advantages may include, but are not limited to, improvements in safety, control (i.e of final product form and physical characteristics), yield, operability, handling, scalability, and efficiency.